Behavioral Genetics class Week One: Intro

To fulfill one of my New Year's resolutions, I'm taking a Coursera class.  Coursera is a website that offers free online college classes in a wide variety of subjects.  I am taking an introductory course in Behavioral Genetics.  I find this subject inherently interesting - I was a psychology major in college - but the main reason I'm taking it is to get some framework for thinking about things with Joshua.  Specifically:

• What kind of  behavioral / personality / cognitive traits are caused by his missing genes (nature)
• What environmental (nurture) interventions can we do to try to help in areas that are more difficult for him. 

I don't expect that this course will speak directly to Joshua's situation, but I'm hoping that it will give me an understanding of the basic concepts in behavioral genetics so that I will have a better idea what I'm doing when I try to research 4Q deletions.

So I'm going to try to do a blog post each week writing about any interesting and helpful things I learn from the course.  This will mostly be for my own memory so I'm not going to put these up on Facebook, but I will put them on my blog so that people can follow along if they're interested.  This is not an attempt to summarize the whole course - it's free and easy to sign up - but just things that I want to remember.
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Week One was an introduction to the field of behavioral genetics.  Points of interest:

• At the beginning of the twentieth century, there was a widespread belief that everything about a person - their personality, intelligence, behavior, etc. - is determined by their genes.  This led to the Eugenics movement, which was an effort to improve human society by influencing who does and does not reproduce.  I read a lot about Eugenics in college, in both my history and psychology classes.  But now that I have a child with a chromosome disorder, it was physically painful to hear a lecture about forced sterilization, "three generations of imbeciles is enough", etc.  Also made me grateful for how far we as a society have come in tolerance towards individuals with differences, even though there's plenty of work to be done towards inclusion.
• In the 1960s, the popular idea was that humans are born as "blank slates" and everything about us is formed by our environment.  The most radical "proof" of this idea was the John / Jane Doe study.  There were two identical twin boys; one was (tragically) accidentally castrated at age one.  Psychologists advised the parents to raise this boy as a girl.  This appeared to go well for the first ten years, and the psychologist published papers stating that this proved the truth of the blank slate theory.  But once "Jane" reached puberty, she started having serious suicidal ideation, so her parents revealed the truth, and she immediately changed her name and gender identity back to male.  (And continued to have psychological trouble for the rest of his life.)  There are so many crazy, where-was-the-ethics-board issues in this story that it would be hard to use it to prove anything -- but it does offer evidence pure "blank slate" theory is an oversimplification.  
• So now psychologists believe that people's behavior, personality, and cognition is a mix of nature and nurture.  Behavioral genetics uses genetics methodologies to study the nature and origins of individual differences in human behavior.
• Pleiotropy - genes can have multiple phenotypic effects (Phenotypic = that which is expressed or observed, such as behaviors and symptoms) (Genotypic = that which is inherited)
• Gene-environment interaction - Genetic effects depend on environmental context.
• PKU - example of inborn error of metabolism.  Children born with one missing gene exhibited all sorts of serious symptoms.  The gene produced an enzyme that helped the body do several different things.  Once the missing gene was identified, the problem could be corrected relatively easily  with a change in diet.  If the problem was not identified early in childhood, it led to severe problems for the rest of the child's life.  This is not the case with every missing gene (that it will lead to such serious problems, but can also be easily treated) -- but it does remind me that I would like to get Joshua a consult with a metabolic doctor if we get a chance.